Piano action with articulated jack

Abstract

A piano keyboard apparatus has an action assembly that includes a four bar linkage having four pivotably connected bars including a whippen pivotably connected to a repetition lever. An articulated jack has a lower link pivotably connected to an upper link and the lower link is pivotably connected to the whippen.

What is claimed is:  
     
       1. A piano keyboard action assembly comprising: 
       a multi-bar linkage further comprising;  
       a whippen pivotably connected to a repetition lever,  
       an articulated jack having a lower link pivotably connected to an upper link,  
       said whippen pivotably connected to said lower link,  
       said repetition lever pivoted to said whippen,  
       said upper link pivotably connected to said repetition lever,  
       a torsional spring disposed between said whippen and said repetition lever so as to rotationally bias said whippen and said repetition lever apart, and  
       said torsional spring comprising a coil having upper and lower spring arms attached to said coil and defining an open angle therebetween wherein said upper spring arm engages said repetition lever and lower said spring arm engages said lower link.  
     
     
       2. A piano keyboard apparatus comprising: 
       an action assembly having a four bar linkage,  
       said four bar linkage further comprising;  
       a whippen pivotably connected to a repetition lever,  
       an articulated jack having a lower link pivotably connected to an upper link,  
       said whippen pivotably connected to said lower link,  
       said repetition lever pivoted to said whippen,  
       said upper link pivotably connected to said repetition lever,  
       a torsional spring disposed between said whippen and said repetition lever so as to rotationally bias said whippen and said repetition lever apart, and  
       said torsional spring comprising a coil having upper and lower spring arms attached to said coil and defining an open angle therebetween wherein said upper spring arm engages said repetition lever and said lower spring arm engages said lower link.  
     
     
       3. An apparatus as claimed in claim  2 , wherein said torsional spring is disposed between said whippen and said repetition lever so as to rotationally bias said whippen and said repetition lever apart. 
     
     
       4. An apparatus as claimed in claim  3 , further comprising a spring tension adjusting means for adjusting biasing force in said repetition spring that rotationally biases said whippen and said repetition lever apart. 
     
     
       5. An apparatus as claimed in claim  4 , wherein said repetition spring is a torsional spring comprising a coil having upper and lower spring arms attached to said coil and defining an open angle therebetween. 
     
     
       6. A piano keyboard apparatus comprising: 
       an action assembly having a four bar linkage,  
       said four bar linkage further comprising;  
       a whippen pivotably connected to a repetition lever,  
       an articulated jack having a lower link pivotably connected to an upper link,  
       said whippen pivotably connected to said lower link,  
       said repetition lever pivoted to said whippen,  
       said upper link pivotably connected to said repetition lever,  
       a torsional spring disposed between said whippen and said repetition lever so as to rotationally bias said whippen and said repetition lever apart,  
       a spring tension adjusting means for adjusting biasing force in said torsional spring,  
       said torsional spring comprising a coil having upper and lower spring arms attached to said coil and defining an open angle therebetween,  
       a slot in an underside extension of said repetition lever, said coil partially retained in said slot, a spring pin disposed through said extension and passing inside said coil, and said upper spring arm disposed in said slot and engaging spring tension adjusting means.  
     
     
       7. An apparatus as claimed in claim  6 , wherein said spring tension adjusting means is a spring tension adjusting screw adjustably threaded in a threaded hole through said repetition lever to said slot. 
     
     
       8. An apparatus as claimed in claim  2 , wherein: 
       said whippen is pivotably connected to said repetition lever by a pinned clevis first joint,  
       said repetition lever is pivotably connected to said upper link by a pinned clevis second joint,  
       said upper link is pivotably connected to said lower link by a pinned clevis third joint and  
       said lower link is pivotably connected to said whippen by a pinned clevis fourth joint.  
     
     
       9. An apparatus as claimed in claim  8 , further comprising a repetition spring disposed between said whippen and said repetition lever so as to rotationally bias said whippen and said repetition lever apart. 
     
     
       10. An apparatus as claimed in claim  9 , further comprising a spring tension adjusting means for adjusting biasing force in said repetition spring that rotationally biases said whippen and said repetition lever apart. 
     
     
       11. An apparatus as claimed in claim  10 , wherein said repetition spring is a torsional spring comprising a coil having a upper and lower spring arms attached to said coil and defining an open angle therebetween. 
     
     
       12. A piano keyboard apparatus comprising: 
       an action assembly having a four bar linkage,  
       said four bar linkage further comprising;  
       a whippen pivotably connected to a repetition lever,  
       an articulated jack having a lower link pivotably connected to an upper link,  
       said whippen pivotably connected to said lower link,  
       said repetition lever pivoted to said whippen,  
       said upper link pivotably connected to said repetition lever,  
       said whippen is pivotably connected to said repetition lever by a pinned clevis first joint,  
       said repetition lever is pivotably connected to said upper link by a pinned clevis second joint,  
       said upper link is pivotably connected to said lower link by a pinned clevis third joint and  
       said lower link is pivotably connected to said whippen by a pinned clevis fourth joint,  
       a torsional spring disposed between said whippen and said repetition lever so as to rotationally bias said whippen and said repetition lever apart,  
       a spring tension adjusting means for adjusting biasing force in said torsional spring,  
       said torsional spring comprising a coil having upper and lower spring arms attached to said coil and defining an open angle therebetween, and  
       a slot in an underside extension of said repetition lever, said coil partially retained in said slot, a spring pin disposed through said extension and passing inside said coil, and said upper spring arm disposed in said slot and engaging spring tension adjusting means.  
     
     
       13. An apparatus as claimed in claim  12 , wherein said spring tension adjusting means is a spring tension adjusting screw adjustably threaded in a threaded hole through said repetition lever to said slot. 
     
     
       14. An apparatus as claimed in claim  13 , wherein said lower spring arm has a lower arm end disposed in an aperture in said lower link and said lower link has a lever arm extending away from said aperture. 
     
     
       15. An apparatus as claimed in claim  14 , further comprising a felt covered angled stop in a whippen slot positioned to contact an angled surface on said lower link. 
     
     
       16. An apparatus as claimed in claim  15 , further comprising: 
       a hammer shank pivoted at a first shank end to a hammer shank flange secured to a shank flange rail,  
       a knuckle depending from said hammer shank and located above a lever pad on said repetition lever, and  
       a hammer including a hammer felt wrapped around a hammer wood molding that is attached to a free second shank end of said hammer shank.  
     
     
       17. An apparatus as claimed in claim  16 , further comprising a stop screw adjustably threaded through said the hammer shank flange positioned above a top end of said repetition lever. 
     
     
       18. An apparatus as claimed in claim  17 , further comprising: 
       an aft whippen end of said whippen,  
       said aft whippen end pivoted to a whippen rail via a whippen flange, and  
       an action bracket supporting said whippen rail and said shank flange rail.  
     
     
       19. An apparatus as claimed in claim  18 , wherein said action assembly is located over a piano key and said apparatus further includes, 
       a capstan screw mounted on and extending upwardly from said key and located directly beneath a depending appendage of said whippen, and  
       a felt covered bottom on said appendage.  
     
     
       20. An apparatus as claimed in claim  8 , wherein said action assembly is located over a piano key and when said piano key is at rest: 
       said second, third, and fourth joints are linearly aligned and said upper and lower links are linearly aligned and locked up.  
     
     
       21. An apparatus as claimed in claim  2 , further comprising a whippen flange pivotably connected to an aft whippen end of said whippen. 
     
     
       22. An apparatus as claimed in claim  21 , further comprising a repetition spring disposed between said whippen and said repetition lever so as to rotationally bias said whippen and said repetition lever apart. 
     
     
       23. An apparatus as claimed in claim  22 , further comprising a spring tension adjusting means for adjusting biasing force in said repetition spring that rotationally biases said whippen and said repetition lever apart. 
     
     
       24. An apparatus as claimed in claim  23 , wherein said repetition spring is a torsional spring comprising a coil having upper and lower spring arms attached to said coil and defining an open angle therebetween. 
     
     
       25. A piano keyboard apparatus comprising: 
       an action assembly having a four bar linkage,  
       said four bar linkage further comprising;  
       a whippen pivotably connected to a repetition lever,  
       an articulated jack having a lower link pivotably connected to an upper link,  
       said whippen pivotably connected to said lower link,  
       said repetition lever pivoted to said whippen,  
       said upper link pivotably connected to said repetition lever,  
       a whippen flange pivotably connected to an aft whippen end of said whippen,  
       a repetition spring disposed between said whippen and said repetition lever so as to rotationally bias said whippen and said repetition lever apart,  
       a spring tension adjusting means for adjusting biasing force in said repetition spring that rotationally biases said whippen and said repetition lever apart,  
       said repetition spring is a torsional spring comprising a coil having a upper and lower spring arms attached to said coil and defining an open angle therebetween,  
       a slot in an underside extension of said repetition lever, said coil partially retained in said slot, a spring pin disposed through said extension and passing inside said coil, and said upper spring arm disposed in said slot and engaging spring tension adjusting means.  
     
     
       26. An apparatus as claimed in claim  25 , wherein said spring tension adjusting means is a spring tension adjusting screw adjustably threaded in a threaded hole through said repetition lever to said slot. 
     
     
       27. A piano keyboard action assembly comprising: 
       a multi-bar linkage further comprising;  
       a whippen pivotably connected to a repetition lever,  
       an articulated jack having a lower link pivotably connected to an upper link,  
       said whippen pivotably connected to said lower link,  
       said repetition lever pivoted to said whippen,  
       said upper link pivotably connected to said repetition lever, and  
       a torsional spring disposed between said whippen and said repetition lever so as to rotationally bias said whippen and said repetition lever apart, and  
       said torsional spring comprising a coil having upper and lower spring arms attached to said coil and defining an open angle therebetween wherein said upper spring arm engages said repetition lever and said lower spring arm engages said lower link.  
     
     
       28. A piano keyboard apparatus as claimed in claim  27  wherein said action assembly includes: 
       a four bar linkage comprising said whippen pivotably connected to said repetition lever,  
       said lower link pivotably connected to said upper link,  
       said whippen pivotably connected to said lower link,  
       said repetition lever pivoted to said whippen, and  
       said upper link pivotably connected to said repetition lever.